The diagram to the below provides an introduction as to some of the interesting phenomena occurring during a 90°-90°-echo sequence.The first two drawings in the left column show the expected effect of the initial 90°-pulse and T2*-dephasing. For illustrative purposes we have selected four...
Hahn-echo extended (HEED) pulse sequences in one- and two-dimensional experiments were successfully applied to phosphorus–nitrogen compounds with two PN bonds {2-chloro-1,3-dimethyl-1,3,2-diazaphospholidine (1), 2-tert-butyl-1,3-dimethyl-1,3,2-dizaphospholidine (2), bis(diethylamino)...
NMR line breadthorganic compounds/ P-N bonded compoundssignal suppressionHahn-echo extended pulse sequencesN-pyrrolyl-phosphorus compounds31P NMR signalsscalar relaxationNot Availabledoi:10.1006/jmra.1994.1054B. WrackmeyerG. KehrJournal of Magnetic Resonance...
Mamoru ImanariElsevier Inc.Journal of Magnetic ResonanceM. Ohuchi, M. Hosono, K. Matushita, and M. Imanari, A new pulse sequence in two—dimensional FT NMR. Solvent elimination using a Hahn echo, J. Magn. Resonance 43 , 499 (1981)....
Coupling constants 2J(15N13CR) and nJ(15N1HR) in 2-substituted pyridines [R = Me (1), CH=CH2 (2), C≡CH (3), C(O)H (4), C(O)Me (5)] have been measured by using Hahn-echo extended (HEED) pulse sequences for one- (1 D) and two-dimensional (2D) 13C/1H NMR (HEED...
Passive observation of 15N satellites in two‐dimensional heteronuclear X–1H shift‐correlated spectra via a Hahn spin–echo extended pulse sequence13C, 29Si, 119Sn 207Pb and NMR1H?X shift‐correlated two‐dimensional NMR1J(15N, X), 3J(15N, 1H)...
Single and double quantum echoes were observed at the value of t = τ and T = 2τ with the laser flash- t -P1 70,ζ1 -τ-P2 140, ζ2 - T pulse sequence , which led to determination of the relaxation time T 23 between the singlet and triplet T 0 〉 states. The relaxation ...
Spin- 7 2 Spin-72 central line intensities are calculated for any ratio of the quadrupolar coupling constant to the radiofrequency field for both one-pulse and two-pulse Hahn-echo experiments and tested by 50 Co NMR on the model compounds, Na 3 [Co(NO 2 ) 6 ] and trans -[Co(en) ...
Through the use of a very simple and well-known pulse sequence (90掳-蟿-180掳) the chemical shift interaction, among others, can be refocused to generate a so-called Hahn echo. If magnetic dipolar interactions with like nuclei and fluctuating interactions with other nuclei may be neglected, ...
In the absence of an NH group, the coupling constants 1J(29Si 15N) were measured from the 15N satellites in 29Si NMR spectra recorded by using the Hahn-echo extended (HEED) refocused INEPT pulse sequence. Isotope induced chemical shifts 1Δ 15/14N(29Si) were also measured by this ...